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ABSTRAK
Secara administratif daerah penelitian terletak di Barat Laut Daerah Pantai Lango, Kecamatan Penajam Paser Utara, Kabupaten Penajam, Provinsi Kalimantan Timur. Secara geografis, lokasi penyelidikan yang memiliki luas sekitar 60,57 Ha terletak pada 116°42'45,11"BT - 116°43'16,01"BT dan 1°8'38,01"LS - 1°8'13,52"LS.
Geologi lokasi penelitian disusun oleh satu formasi, yaitu formasi Pulaubalang yang berumur Miosen Tengah. Struktur geologi yang berkembang di daerah penelitian berupa lipatan antiklin berarah Timur Laut – Barat Daya dan lipatan sinklin diperkirakan relatif berarah Timur Laut – Barat Daya.
Morfologi daerah penelitian tergolong dalam bentang alam dataran rendah, dengan ketinggian berkisar antara 6 m – 25 m di atas permukaan laut. Kemiringan lereng umumnya 0,50 atau 0,9% sampai 5,90 atau 10,3% sehingga masuk dalam kelas lereng datar hingga landai, dengan morfogenetik berupa denudasional.
Stratigrafi daerah penelitian tersusun atas empat macam litologi, yaitu batubara, batupasir, batulempung dan batulanau. Dengan klasifikasi tanah di daerah penelitian berdasarkan USCS adalah CH, ML, MH, SC, SM dan GM. Berdasarkan nilai UCS terhadap contoh batuan inti bor, klasifikasi tanah kohesif dan batuan adalah Very Stiff Soil hingga Very Weak Rock. Berdasarkan perhitungan nilai RMR, kelas batuan penyusun daerah penelitian termasuk dalam kelas Very Poor Rock dan Poor Rock.
Untuk mendapatkan nilai FS stabil, dilakukan beberapa simulasi analisis kestabilan lereng pada setiap kedalaman dengan interval 10 meter hinga terget kedalaman 70 meter, masing-masing kondisi satureted, saturated dengan pengaruh seismic load, dewatering, dan dewatering dengan pengaruh seismic load.
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ABSTRACT
Research area administratively is located in Northwest of Pantai Lango
Region, District of Penajam Paser Utara, Penajam Regencies, East Kalimantan
Province. Geographically, the research area which has an area of approximately
60.57 hectares located at 116 ° 42'45, 11 "BT - 116 ° 43'16, 01" BT and 1 ° 8'38,
01 "LS - 1 ° 8'13 , 52 "LS.
Geological sites compiled by one formation, the Pulaubalang Formation
with age in Middle Miocene. Geological structures that developed in the research
areas are anticline folds with direction of the northeast to southwest and syncline
folds with direction of the southwest to northeast.
Morphology of the research area belongs to the lowland landscapes, with
altitude ranging between 6 m - 25 m above sea level. Slope is generally 0.50 or
0.9% to 5.90 or 10.3% classfied as flat to gentle slope, with morphogenetic is
denudasional.
Stratigraphy of the study area is composed of four kinds of lithology,
namely coal, sandstone, mudstone and siltstone. With the classification of soil in
the research area based on the USCS is CH, ML, MH, SC, SM and GM. Based on
the UCS of the rock drilling core samples, the classification of cohesive soil and
rock is Very Stiff Soil to Very Weak Rock. Based on the calculation of the RMR,
the class of rocks making up the research area included in to the class of Poor
Rock and Very Poor Rock.
To get the value of FS is stable, some analysis of slope stability
simulations for each depth with interval 10 meters until target depth in 70 meters
is done, respectively each conditions are saturated conditions, saturated with the
seismic load effects, dewatering, and dewatering with the seismic load effects.
By some simulations that are performed, the stable slope and
economically will be obtained when slope of pit in unsaturated condition and
